What Is Hyaluronic Acid And How To Use It

Hyaluronic Acid 2% + B5 from The Ordinary


Hyaluronic acid – on everyone’s lips (not literally) in the skincare community these days. But what is it, what is it good for and how should you use it? I’ll give you the answers, plus show you my favourite.

Hyaluronic acid (HA) is a glucosaminoglycan polysaccharide (think a long chain of paired sugar molecules) occurring naturally in dermis of our skin, where it acts as a natural humectant. 



The natural occurring HA functions as a sponge in the dermis to hold and release water as necessary. When applied to the skin, either as serums or in moisturizers, topical humectants draw water from the dermis up to the epidermis and stratum corneum (the outmost layer of our skin). Instantly they allow the skin to feel smoother by filling gaps in the stratum corneum through swelling. Used properly and in the right chemical formulation they can relieve dry skin conditions, such as eczema, psoriasis and atopic dermatitis, and improve the barrier function via its hydrating properties. 


The chemical structure of hyaluronic acid – shown in a so-called Haworth projection




They are also able to draw water from the environment – which is what we want it to do – but only if the surrounding humidity exceeds 70%. However, in air conditioned spaces, where the humidity is well below 70%, topical humectants will instead pull water from the deeper epidermal and dermal tissues to rehydrate the stratum corneum. (I had to google the outdoor humidity where I live. It’s currently 74% – phew. For all the Danish readers, you can find your local humidity on dmi.dk
The moisture that is being pulled up from the deeper layers of the skin will evaporate faster, thus resulting in the opposite effect than intended, namely dehydration. This is why it is recommended to apply a so called occlusive (found in regular moisturizers) afterwards, to seal the moisture to the skin. 

Hyaluronic Acid 2% + B5 from The Ordinary has been a game changer for my dry skin. It contains three different HAs, including a HA crosspolymer, which plumps and hydrate my skin, without drawing water out of my skin. It has fast become a staple in my skincare routine (hence my personal stock of 6 bottles). In combination with the Glycolic 7% Toning Solution it has freed me from my otherwise chronic dry patches around my nose and helped even out the texture of my skin. 



When sold isolated, as this formula from The Ordinary, you should use it as serum. That is after cleansing and before you apply your SPF/day cream/night cream/face oil.

Apply 3-4 drops in your palm and distribute it across your face and neck.

This aforementioned swelling is especially visible around the pores on my nose and the fine lines in the outer corners of my eyes. Straight after application I apply my SPF in my AM-routine or moisturizer or oil in my PM routine, to seal the deal.

I hope you found this useful. Please follow me on Instagram https://www.instagram.com/makeupandmedicine.dk/ and tag me in your pictures if you purchase any products from The Ordinary. I would love to hear your thoughts. 

This is not a sponsored post and it is without affiliations. This product is purchased by me.

XO Cæcilie


Cosmetic Dermatology: Products and Procedures, Second Edition. Edited by Zoe Diana Draelos. © 2016 John Wiley & Sons, Ltd. Published 2016 by John Wiley & Sons, Ltd. 


  1. Katrine
    14. September 2017 / 12:44

    Hi Cæcilie,

    Would you use this when pregnant or breastfeeding?

    Thank you:-)

    • 18. September 2017 / 12:31

      Hyaluronic acid is not on the list of suspected endocrine disrupting chemicals allowed in personal care products. So not an EDC to our current knowledge. As with all ingredients it’s really a matter of research. However, I’ve been using this while breastfeeding. XO Cæcilie

      • Katrine
        21. September 2017 / 7:37

        Thank you so much!

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